The present invention relates to a vehicle windshield wiper whose wiper link mechanism is improved so that a windshield can be wide wiped.
Lately, a safe and comfortable driving is required of a vehicle. Therefore, the vehicle is designed like a slant of nose, and a bonnet and a dashboard are fixed below not to appear in a driver's vision area, resulting in a good view and a wider area of the windshield. Thus, a windshield wiper also should be desirably useful in a safe driving by wiping not only a wipe area provided by the regulation for wipe area, but also an area between a lower view provided by the reglation and a bonnet.
Conventionally, the Japanese utility model open publication No. '86-153658 discloses a vehicle windshield wiper wherein a first wiper blade on the driver's side and a second wiper blade on the passenger's side are coupled with a driving power via a link mechanism to wipe a front windshield. By the link mechanism, the second wiper is adapted to be displaced from passenger's side edge to lower edge on the driver's side at a twice speed of the first wiper blade. This vehicle windshield wiper uses the link mechanism of a tandem drive system wherein two linear swinging levers are coupled by a coupling rod. However, in case of using of the conventional system for wipe angle of 180.degree., undesirably the swinging lever on the passenger's side is short and the link mechanism is so loaded that a vehicle body is not deemed as a rigid body. To widen a swinging angle, the use of a double arm lever is proposed as disclosed in the German patent No. 1164858. However, in a conventional double arm lever, a shaft is provided in either one of two arms composing the double arm lever and a coupling rod is coupled with the shaft. Therefore, the interference occurs between the arm and the coupling rod, resulting in limitation of a fully wide angle for wider wiping. Furthermore, because a driving-side wiper blade and a driven-side wiper blade are reversely swung at the same time, the both wiper blades interfere with each other, so a windshield cannot receive a wide wipe angle to a lower edge thereof.
U.S Pat. No. 4672709 discloses a drive for a tandem wiper system wherein a driver's primary vision area is double wiped by a motor 64. The drive for the windshield wiper system includes a driver's side transmission and a passenger's side transmission. An axis 38 of a tower 36 in the transmission 32 is swung by the motor 64 via a crank arm 68, a drive link 70, a ground link 52, a connecting link 60 and an elongated drive plate 44. Because the tower 36 and the ground link 52 interfere with each other, a windshield is not wide wiped by a passenger's side wiper blade. As a result thereof, a driver's side windshield cannot be wiped to a lower view being a lower edge 14.